The invention concerns a coating system for running webs of paper or cardboard carried by two moving surfaces wherein the coating substance is first applied on one moving surface carrying the web and then transferred in a press gap to one or both sides of the web. Such a system is known from GB-B 21 03 115. In this system, both size and pigmented dye can be used as coating medium. The two press rolls form a press gap through which the web is passed and in which the coating substance, which is contained on the shell surface of the press rolls after having previously been applied there in dosed fashion, is transferred. This device is usable for relatively high web speeds. But with web widths, the lengths of press rolls and notably their diameters becoming ever larger today, high web speeds involve the risk of so-called film splitting; refer in this respect to FIGS. 12 and 13 of the VOITH Publication No. "p 2766". Film splitting occurs on the exit side of the press gap as the shell surfaces of the two press rolls diverge from each other. This effect is influenced by the adhesion of the coating substance to the press rolls and a relatively slight pressure in the coating substance in this area. The result is a reduction in the surface quality of the finished paper or cardboard web.
As regards the prior art, reference, for the sake of completeness, is made to DE-GM 90 07 025, DE 14 25 060 and U.S. Pat. No. 5,252,186.